Been there some 15 years back, and loved it. The locals are the friendliest and most welcoming people you could imagine. They shove each other around rather a lot, in their own bars and clubs, but never ever seem to get into anything serious. The indiginous are dirt poor, but will give you everything they have to make you feel comfortable. If you can pick up a few cheapo things before you go, like watches or musical instruments or anything, to give as gifts to people there, do it. They are usually wonderful, and they love to get simple stuff given to them, as they'll usually not be able to buy that stuff for themselves.
Take the buses, you can meet locals easier, and sit and talk with them on the way.
Go to the 'desert islands' if you can, even if only for a day out. The sea is bath warm.
The mosquitoes are horrendous. Be sure to sleep under a net, and do not let any of the net touch your skin as they'll land on it and suck your blood from through the net anyway.